Circuit module with pins conducting heat from floating plate contacting heat producing device

Abstract

An improved TCM-like circuit module for cooling an array of chips mounted on a substrate. The substrate and the chips are enclosed by components that include a barrier plate that separates the chip space from a coolant such as air or chilled water. A floating plate contacts a heat transfer surface of each chip and forms a local heat sink. Pins conduct heat from the floating plate. In one embodiment, one end of each pin is rigidly attached to the floating plate and the other end is located in a cavity in the barrier plate. In a second embodiment, the cavities are formed in the floating plate and the barrier plate rigidly supports the pins. In the second embodiment, the pins can be extended through the barrier plate to contact the coolant directly.

What is claimed: 
     
       1. In a circuit module which has a planar dielectric substrate and an array of one or more heat producing devices such as semiconductor chips mounted on a surface of the substrate, the substrate being oriented for purposes of terminology in a horizontal plane with the devices on the upward facing surface, each of the devices having an upper surface that is substantially flat,   a plate cooperating with the substrate to form at least part of an enclosure for a space containing the heat producing devices and overlying the devices and forming a barrier between the devices and a coolant,   improved means for transferring heat from the devices to the coolant, comprising,   at least one floating plate for each device, and means for holding the lower surface of the floating plate in heat transfer contact with the upper surface of the associated device,   a set of pins for each said floating plate, said barrier plate supporting said pins with the pins spaced apart in a row and column array, said pins extending vertically downward to said floating plate, said floating plate having cavities for receiving the lower ends of the pins for heat transfer through a gap that permits the floating plate to adjust to variations in the position of the associated device, said pins extending upward through said barrier and support plate into the coolant space where the tops of the pins form fins for transferring heat to the coolant, whereby said pins form a continuous path for conduction independent of the barrier and support plate.   
     
     
       2. The circuit module of claim 1 wherein the size of at least one device is approximately a multiple of the size of the floating plate and wherein said module includes a plurality of said floating plates in heat transfer contact with said one device and a set of pins for each floating plate. 
     
     
       3. The circuit module of claim 1 wherein the pins are cylindrical in cross section and the cavities have cylindrical walls. 
     
     
       4. The circuit module of claim 1 wherein said barrier and support plate is of a heat conducting material and forms at least part of said heat transfer path between said pins and the coolant. 
     
     
       5. The circuit module of claim 1 wherein the devices are spaced apart on the substrate and wherein the floating plate extends beyond the edges of the device into the space between devices sufficiently to provide an improved heat transfer path through heat spreading. 
     
     
       6. The circuit module of claim 4 wherein said barrier plate is of a heat conducting material and said pins are attached in a thermal conductive relationship to said barrier and support plate whereby said barrier and support plate forms at least part of said heat transfer path between the pins and the coolant. 
     
     
       7. The circuit module of claim 5 wherein the rows and columns of pins are equally spaced apart by a distance that is related to the size of the heat producing devices such that there is at least one row or column of pins immediately outside each edge of each device and there are at least two rows or columns of pins between adjacent edges of adjacent devices, and   said floating plate extends beyond the edges of the associated device sufficiently to underlie a row or column of pins along each underlying edge of the floating plate and   said floating plate has cavities to receive said pins along each edge.   
     
     
       8. The circuit module of claim 7 wherein said cavities for said row or column of pins along each underlying edge of the floating plate extend through the plate and wherein the corresponding pins extend approximately through the plate for extended contact between the pin and the plate.